'Carb cleaning?' Spraying some red wand juice at the carburetor bellmouths? I find little of any value in this video. Remove the carburetors, strip them, and give them a trip into the ultrasonic bath. blow-out the passages, reassemble them, dry-set the float level, finish the reassembly and re-mount them. Get it running, warmed-up and synchronixze the carburetors. Re-install the air filter, and that should get some results.
I'd check the brass to see what's been installed in the past. There may be a mish-mash of different parts OEM and/or aftermarket. Get back to OEM specs and maybe 150 or 147.5 on the mains, and you probably will be much-happier with how it runs, compared to the video efforts. Or should I say,
lack of efforts?
Do searches on here for threads of use in cleaning your carburetors, and then setting them up and in-place, and you should be much-happier. The air filter needs to be in-place to work the carbs properly. With your four carbs/filters, they all need to be mounted properly and free of intake leaks. The canister between the rear cylinders is an oil mist condenser which allows oil to drain back into the engine via a line to the oil filler plug.
The pilot jet, in the jet block, which is the smallest brass passage. It can plug frustratingly-often, if you have trash in the gas tank, like rust, or a dirty gas filter, or contaminated gas. That includdes water in the float bowls, drain the individually into a clear container to expose the presence of any water floating in the gasoline drained from each float bowl. The water forms a 'lens' of different specific gravity from gasoline, easily seen if there is any amount of water present.
The stainless steel wire sticking out of the pilot jet is just there to show sometimes you may need to physically-remove hardened deposits which aren't removed by the ultrasonic bath operation. I use a single strand like this and a finger-vise to carefully remove any hardened deposits.
Here's what it should allow you to see when clean: all the way through the pilot jet.
A diagram of the carburetors. Some of the carb bodies are no-longer available new, from Yamaha.
https://ia800204.us.archive.org/14/...ice-manual/yamahavmaxvmx12-service-manual.pdf
Save a copy of the service manual to your computer and print-out a copy and place the copy in a 3 ring binder for easy shop reference.
These K & L carburetor rebuild kits are found on ebay, and are less-expensive than the OEM parts.
The above kit, labelled as to where the pieces go.
Some threads to help with carburetor work. If the link takes you to a post not at the beginning, I suggest you start at the beginning to ensure that your knowledge base becomes more-complete as you read
all the contents. This is not a complete list of all the carburetor posts! There are hundreds, perhaps thousands of those.
https://www.vmaxforum.net/threads/new-member-looking-for-any-info-i-can-gather.52866/#post-530792
https://www.vmaxforum.net/threads/carb-tune.51215/#post-515727
https://www.vmaxforum.net/threads/something-is-heating-up.51864/#post-522866
https://www.vmaxforum.net/threads/o-ring-and-carb-needles.48940/#post-487970
https://www.vmaxforum.net/threads/help-help-cylinder-3-not-firing.49065/#post-489443
https://www.vmaxforum.net/threads/new-owner-of-an-89-vmax.49075/#post-489386
https://www.vmaxforum.net/threads/make-old-carbs-new-again.46136/#post-467897
